You sound like an ideal candidate for the GAPS diet.
As for brain boosters... sorry I can't think of any. When I lower my carbs my mood and cognition are much more relaxed, much more focused. If you find you need carbs, some berries or an apple to keep you going can't hurt. A history of coffee can lead to adrenals that are less than optimal, maybe you need to give them time to recover. And as always get enough sleep.